An alternate SHA Interleave algorithm as implemented in the SRP
distribution. This version reverses the even and odd byte streams before
performing the SHA digest.
This product includes software developed by Tom Wu and Eugene
Jhong for the SRP Distribution (http://srp.stanford.edu/srp/).

Completes the digest computation by performing final
operations such as padding. Once engineDigest has
been called, the engine should be reset (see
engineReset).
Resetting is the responsibility of the
engine implementor.